fix subscription id type

[AllyW]

---

This checklist is used to make sure that common guidelines for a pull request are followed.

Related command

az spring-cloud create

General Guidelines

• Have you run azdev style <YOUR_EXT> locally? (pip install azdev required)
• Have you run python scripts/ci/test_index.py -q locally?

For new extensions:

• My extension description/summary conforms to the Extension Summary Guidelines.

About Extension Publish

There is a pipeline to automatically build, upload and publish extension wheels.
Once your pull request is merged into main branch, a new pull request will be created to update src/index.json automatically.
You only need to update the version information in file setup.py and historical information in file HISTORY.rst in your PR but do not modify src/index.json.

[yonzhan]

spring

[azclibot]

[Release] Update index.json for extension [ spring-cloud ] : https://dev.azure.com/azclitools/internal/_build/results?buildId=42118&view=results